Table E. - Temperature correction factors for the
power factor of power transformer windings*
F
P20
=
F
K
PT
where:
F
P20
= power factor corrected to 20
E
C
F
PT
= power factor measured at T
E
C
T =
test temperature
K =
correction factor from table
Test temperature T
O
C
Correction factor K
10
0.80
15
0.90
20
1.00
25
1.12
30
1.25
35
1.40
40
1.55
45
1.75
5O
1.95
55
2.18
60
2.42
65
2.70
70
3.00
* From IEEE Standard No. 262, 1973.
45